System for controlling the operation of elevators



Jan. 15, 1924. 1,481,119

F. A. BOEDTCHER SYSTEM FOR CONTROLLING THE OPERATION OF ELEVATORS Filed May 25, 1920 Snvewtoz Patented J an. 15 1924 UNITED STATES PATENT OFFICE.

SYSTEM FOR CONTROLLING THE OPERATION OF ELEVATORS.

Application filed May 25,

To all whom it may concern;

Be it known that I, FRANZ A. Bonntrcnna, a citizen of the United States, residing at Bergenfield, county of Bergen, and State of New Jersey, have invented a certain new and useful System for Controlling the Operation of Elevators, of which the following is a specification.

This invention relates to elevator operating systems, and is, more particularly, directed to the governing of the car controlling circuit, for the purpose of effecting proper and safe operation of the car at all times.

In elevator systems as hereinbefore installed, it has been the practice to control these circuits, in such manner, that the elevator car is precluded from starting from a floor at which it is previously stopped until the shaft door at said floor has been closed. This is for the purpose of protecting persons from walking through shaft doors, which have been left open, after a car has left the floor, and, for the further purpose of precluding the car operator from starting the car while passengers are leaving or entering the same through the floor opening. Vhile these systems have been very useful in the overcominlg of accidents of this character, such systems have led to the dangerous practice, on the part of car operators, to throw the controller into a full speed position, while the floor door is open, so that the car will start at full speed, as soon as the door is closed, and the controller circuit completed by the switch normally associated with the floor door. The purpose of this practice is to obtain rapid service, but it will be manifest to those skilled in this art, that the sudden imposing of the full force of electrical energy upon the motor, which operates the car, through the carrying out of this practice, results in such an inrush of current to the armature, that the burning out thereof not infrequently occurs. Moreover, the sudden starting of the car from a dead stop to full speed imposes a tremendous strain upon the operating 'mechanism of the elevator and the cables which support and carry the same, thus rendering the practice specified very dangerous and at times highly expensive because of repairs, and adjustments necessitated thereby. In fact, elevator cars are 1920. Serial No. 384,117.

very often overloaded, or at least loaded to their maximum capacity, with the resultthat the sudden acceleration of the operating mechanism, as described, places an overload on the cables which may cause them to snap with serious loss of life.

With these considerations in mind, one

f the objects of the present invention is to provide an elevator controlling system, wherein it is normally, absolutely impossible for a car operator to start the car, except from neutral. That is to say, a system wherein the car can only be started by operating the controller circuit successively through its different speeds, starting at the lowest.

In the elevator controlling systems as heretofore installed, it has further been suggested to provide a controller circuit with a switch, which it was required to close before the controller circuit could become opera tive to effect movement of the car. This switch was electrically controlled and was included in a circuit also including switches controlled by the opening and closing of the floor doors. The door switch circuit was usually of the open circuit type and the door switches were so constructed, that when any door was open, the switch circuit was closed and served to open the switch which governed the controlling circuit. This con-, struction operated with high efficiency so long as all of the electrical connections and wiring remained intact and were properly insulated. As soon, however, as ground occurred in the door switch circuit or one or more of the fuses, which are normally included in switch circuits, blew out, the switch controlling the operating circuit of the elevator frequently became permanently closed so that the car could be operated at will and entirely beyond the control of the door switches with the result that the car could pass up and down the shaft with all of the doors open.

With these considerations in mind, a sec ond object of the present invention is to provide an elevator controlinlg system, wherein the grounding of any portion of the door switch circuit, or, a breaking of said circuit, due to the blowing of the fuses or the leaving of a floor door in dangerous condition, while the car is at rest at a floor, will preclude the movement of the car and immediately apprise the operator thereof that something is wrong with the door switch circuit. In such instances, however, he has recourse to emergency means, which will enable him to move the car fo" the purpose of detecting the cause of the failure of the door switch circuit to operate and to allow any passengers who may be in the car to leave the same at an adjacent floor. The ob ject of the emergency means is particularly to overcome any chance of a car being stalled between floors.

The use of emergency means for the purpose of allowing the movement of a car after the controlling circuit has been autoinaticall rendered inoperative, for any one of several reasons, has been heretofore carried out in practice, and the emergency mechanism has been st univen ally of the electrically operated type, and has generally been controlled through a push button or other form of switch positioned in the car and normally protected against tampen ing by inquisitive persons through the housing of said switch within a casing having a glass closure. In the event of trouble, the operator is supposed to brcalr the and operate the switch to enable him to move the car independently of the door switch circuit. There is a strong tendency on the part of operators, however, to become careless and it very frequently occurs that, a door switch circuit cease to oierate, the glass closure is broken and the emergency switch thrown on to render the car opera tive, not only for immediate necessities, but for continued operation. In other words, after the emergency switch has been operated, the car operator finds that he can operate the car satisfactorily and does not bother to lay up the car for repairs of the circuit, but continues to operate the same through long periods of time without the protection of the door switch circuit, whereby the doors of the elevator shaft may be left open or closed at will. without in any wise effecting any control of the operations of the elevator car without the safety normally incident to the use of such circuit.

Moreover, a third object of the present invention is to provide emergency means with which it is practically impossible to operate the elevator for any appreciable time after the door switch circuit has become ineffective. In the preferred embodiment of the invention, the door switch circuit is controlled at the respective floors by the floor door looks so that it becomes, in efiect, a door lock circuit which can only be operated throughthe actual locking or unlocking of the door and independently of any movement of the door. Preferably, this circuit is of the open circuit kind, being closed when all of the loclrs are in locked condition, whereby the unlocking of any particular loci: brings about the breaking of the circuit and renders the same inoperative.

In contradistinction to the electrically controlled emergency means of the prior art, the emergency means of the present invention is entirely mechanical and is furthermore entirely independent of the door switch circuit. It is thus not dependent for its operation on the door switch circuit, as is practically every prior electrical emergency device for electrical elevators, and, accordingly, cannot.

be rendered inoperative by the failure of the door switch. circuit to operate.

A fourth object of the present invention is to so construct an elevator controlling system that the controlling circuit n lly governed by a switch which is it to be positively and mechanically close i, is adapted to be thereafter and while the car is at rest at a iioor, maintained closed by a door switch circuit which, of itself, ones notpossess the ability to close said switcln In other w rds, the door switch circuit becomes, practically speaking, purely a maintaining circuit and not a switch operating circuit as has universally been the case in prior constructions. lly so constituting this system, an operator is positively precluded from starting an elevator except through successive speeds and cannot start it on high. For the reason that, if the controller is out of neutral when the door switch circuit is completed, said circuit is incapable of closing the switch of the controller circuit and the car will simply remain at a standstill untilthe controller is moved to neutral position and then operated in the proper manner.

Features of the invention, other than those specified, will be apparent from the hereinatter detailed description, taken in conjunction with the accompanying drawings.

The accompanying drawings illustrate one practical embodiment of the invention, but the constructimi therein shown is to be understood as illustrative, only, and not as defining the limits of the invention.

iihc drawings illustrate dia .ammaticall a system embodying the present invention.

Referring to the drawings, 1 designates a floor or platform of an elevator car which is mounted for vertical travel in an elevator shaft as common, and the car is fitted with. a suitable controller 2 having a handle 3 b means of which the controller may be operated for the purpose of controlling the r' ovcments of the car. The handle 3 of the controller is mounted on a controller lever a; which carries movable contacts adapted to be shifted through the operation of the handle into engagement with fixed contacts for the purpose of effecting movement of the car in either an upward or downward direction depending on the direction of rotation of the lever 4 from the neutral position in which it is shown in full lines in the drawings. The controller construction described forms no part of the present invention and may be of any conventional form, but has been referred to briefly to facilita to a thorough understanding of the present invention. ertain of the fixed contacts of the controller are electrically connected through wires 6 and 7, through suitable electrical means with the motor and correspond, respectively, to the upwardly and downwardly directions of movement of the car, and certain other of the contacts 5 are connected by a common wire 8 to the motor, whereby a circuit through the controller may be completed either through the wires 7 and S or through the wires 6 and 8 depending upon the direction in which it is desired to more the car. Included in the common wire is switch mechanism 9, which may be mounted in any suitable position on the car either above the platform and suitably housed or below the platform. By means of this switch mechanism the controller circuit for the motor may be governed so as to render said circuit operative or inoperative.

The switch mechanism, which is designated generally by the reference numeral 9, embodies an insulating supporting plate 10 to which is pivoted a. rocker 11 on a pivoted pin l2. The rocker ll embodies a bridge shaped member 13, preferably of metal having rigid therewith a non-magnetic portion 14 having a foot 15 provided with an aperture 16. The free end of the bridge member 13 is provided with an apertured tail piece 17 and carries a forwardly projecting pin or stud 18. The stud 18 works in the bifurcated end of a movable switch member 19 pivoted on a pin 20 which is, in turn, supported on a bracket 21. The bracket 21 is secured to the plate 10 by means of screws 22, one of which serves as a binding post for one lead of the wire 8. lVhen the rocker is tilted such movement thereof is adapted to cause pivotal movement of the switch member 19 to bring the same into and out of engagement with a fixed contact 28 which is mounted on the plate 10 by means of screws 24 one of which serves as a binding post for the other lead of the wire 8. Thus, through the rocking movement of the rocker 11, the switch embodying the fixed contact 23 and the movable contact 19 may be opened or closed to govern the operativeness of the controlling circuit through the common wire 8.

The rocker 11 may be constructed of metallic and nonmetallic material as specified or may be constructed entirely of non-metallic material, so long as an armature 25. which is carried by the portion 14 is insulated from the rocker. The armature 25 is mounted on the rocker 11 for cooperation with a core- 2-(3 of a magnet 27 and is preferably coiled around the core as shown. The magnet and its core are secured to the plate 10 by means of screws 28.

The coils of the magnet 27 are included in a door switch circuit 29, which circuit also includes a plurality of door switches 30, one of which is positioned adjacent the door oi'- each floor of the elevator shaft. The switches are so constituted that they tend to assume an open position either under the influence of a spring 31 or by gravity or in any other suitable manner, but are adapted to be normally held closed at such times as the elevator door is in closed and locked position by means of a portion of the lock of said door. For an illustrative showing, 32 designates the locking latch of the lock pivoted at 33 and adapted to cooperate with the keeper 3-1. When the latch in engagement with the keeper, the door is locked in closed position and the weight of the latch rests upon the switch and causes the closing of the switch. However, as soon as the latch is raised to unlock he door, the switch automatically opens and breaks the circuit 29. As soon as the door is again locked, the switch again is closed by the latch. Accordingly, the locking and unlocking of the door controls the door switch circuit and even though a door is closed and the lock fails to operate to lock the door in closed position, the circuit 29 will remain inoperative until the door is locked. The system of this invention, accordingly, does not rely for its operation upon the opening and closing of the door which at times would be very apt to leave the door switch circuit in operative condition, while the doors were left in an unsafe condition, wherein they could be opened by unauthorized or curious persons with the result that accidents co ld occur.

The door switch circuit 29 is energized from any suitable source and embodies fuses 35 and 36 in its leads. Particular attention is moreover called to the fact that the positive lead of this circuit passes directly to the door switches which are connected in series and that the negative lead passes directly to the coil 27. This is a very important feature from a practical standpoint since any grounding at he switches will immediately render the coil 27 inoperative and probably blow the fuse 35. If the polarity of the loads were reversed, any ground in the lead which passes directly through the coil 27, so long as it occurred at the distant side of the coil as, e. g, in one of the door switches, would leave the coil in an energized condition and would not immediately render it dead as with the polarity illustrated in the drawing. W ith the coil 27 constantly energized, the car might be run at will whether the doors were locked or unlocked. Accordingly, the parts of the system should be wired as shown, so that any grounding at the door switches or in any other part of the positive lead will immediately render the coil 2. dead.

Another important feature of the present invention is inherent in the fact that the cur rent in the door switch circuit 29 is so weak that it will not normally attract the armature 25, for the purpose oi? closing the switch in the wire 8. in practice, the bridge portion 13 is made heavier than the portion 14, so as to normally gravitate into a position to disengage contacts 19 from contacts 523 in the controller lead 8, and simultaneously lift the armature 25 away from the core ot the coil 1-7. Under these conditions, the circuit 29 is o'l insullioient strength to attract the armature 2:) and close the switch in the con troller lead. However. ii the rocker ll is tilted to bring the a ature into engagement with the core 26, while the door switch circuit 29 is completed and energized, said circuit is of suliicient strength, in the ab sence of the gap between the armature 25 and its core to hold the rocker in this position and maintain the switch of the controller lead closed. The door switch circuit 29 bus becomes what may be termed a main taining circuit and is not to be confused with operating circuits, since it has not the power to attract its armature and close the switch, but merely serves to hold the s itch closed after said switch has been placed in this condition, through the employment of means associated with the controller. Il id maintaining circuit thus has an entirely t it- -lerent function from that which would be the case if it were in the form of an ope "ating circuit adapted, of itself, to close the switch of the controller circuit, and as will be hereinafter more fully explained accomplishes an entirely difierent result occasion ing absolute safety in the operation of the system.

The switch of the controller circuit is adapted to be closed through the tilting of the rocker ll by means operated by the controller and, as shown, this means consists in a iluralily of weights 87 secured to a rod 38 which passes upwardly through the aperture 16 in the foot of the rocker and is provided with a stop 39 as shown. The weights when imposed on the rocker through the rod 38 and stop 39 ovcrbalance said rocker, close the switch in the controller lead 8, and bring the armature into operative relation with the coil 27, and this is the position which the parts occupy when the controller lever l, to which the rod 38 is connected by a flexible connection 40, is in neutral position as shown with the elevator car at a standstill. The flexible connection runs over a pulley 41 so that when the controller lever is moved from the neutral position shown to a position shown in dotted lines, wherein it adapted to support the elevator, the weights are lifted and the stop 39 raised to the dotted line position. If all the elevator door 1001:5132 are in locked condition, the lead 8 of the controller circuit will be completed at the switch 19, and said circuit will be completed through the lead 7 to eilect movementor' the car. This is for the reason that the maintaining circuit will be energized and its coil 27 will hold the rocker in a tilted position to close the switch at 19.

However, if at the time of shifting the controller lever, one of the door locks is un' locked, the COll'GSPOUCliIlg switch thereof will be open and as soon as the weights 3? are lifted, the switch in the lead 8 of the controller circuit will be opened and the car cannot start. For the same reason, an operator cannot move the controller lever on to a given speed while a door isopen and cause the elevator car to automatically start when the door is closed and looked as is the case in prior systems because this would leave the rocker in a position to break .the controller circuit and when the door was locked the maintaining circuit, while completed, would be of insufficient strength to close the switch and start the car. With the present invention, the car must be started by the controller from a neutral position.

There are times in the operation or" an elevator when it is desirable to be able to move the same irrespective as to whether the door switch circuit is operative or not, such, e. g., as in case or" fire when said circuit may become grounded, in case moisture should ground said circuit, or in the event that some unauthorized person should reach in through the floor door and unlock the same. In any of these instances, the troublemight occur while the elevator car is between floors in which event, the car would, under the safety provisions of this system, immediately stop. For this reason, emergency means is provided which will allow of the further operation of the car to enable the same to be moved to a position to allow of the exit of any passengers who might be aboard, or to permit of the running of the car in case of lire so tnat the occupants of the building may be rescued.

Emergency mechanism has heretofore been used, but is invariably electric and usually forms part of the door circuit. In either instance, trouble with the door circuit or fire is apt to render the emergency means inoperative thereby greatly endangering the lives of the persons in the car or building. According to the present invention. the emergency mechanism is made entirely independent ol the door circuit and is further more purely mechanical. It consists in the illustrative form shown of a rod 4-2 which passes through the aperture 17 of the tail piece on the rocker and has a stop .43 at the lit) lower end thereof. The upper end of the rod is ailixed to one end of a lever 44 piv oted at 45 and provided at its other end with a finger piece 46. T he lever 44 is housed within a suitable casing 47 positioned in any convenient place within the car and the finger piece 46 protrudes through one end of the casing. However, the lever is normally precluded from operation by a plate of glass 48 which is positioned within the casing and forms a strut. or obstruction to the downward movement of the finger piece.

In case of emergency, the operator may break the glass 48 and thereafter push down the finger piece 46 which will rock the rocker in a countercloclnvise direction and close the switch of the controller circuit at 19. However, in order to operate the car such operator must hold the finger piece 46 down for as soon as he releases it the parts will gravitate to a position to open the switch. In this manner, the car is rendered operable during emergency but the finger piece 46 cannot be pushed down and left in this position to allow of continued use of the car. This permits of operation of the elevator in case of fire, but is so inconvenient that an operator would not otherwise attempt to run the elevator through the controlling period, as one of his hands must constantly be employed when the elevator is running to hold down the finger piece 46. Accordingly, the heretofore prevalent tendency to simply switch out the floor switch circuit in case anything became wrong therewith and to operate the car indefinitely without the pro tection of such circuit is overcome by the present invention and the operator is practically forced to operate his car under maximum conditions of safety.

In the invention, as thus far specifically described and shown in the drawings, the controller circuit is of the single wire type, but, there are other well known forms of controller circuit embodying double or triple wiring. It will be understood that the single wire circuit shown in the drawings is for the purpose of illustration, only, and that if the wire 8 is duplicated for double, triple, or more circuits, the switch in said circuit is merely duplicated and all of these switches may be secured together as willv be understood by any one skilled in the art, so as to be ope ted from a single gravity mem her as described in connection with the single circuit.

Moreover, while the invention has been specifically described as particularly adapted for use in governing the controller circuit of the car, it will be understood that the switch described as in the wire 8 of the controller circuit, might be left out of this circuit, and, instead, included in the operating circuit of the elevator Without depart ing from this invention. In this event, the

controller circuit would be completed, as soon as the controller handle is thrown over, but the operating circuit would be broken unless all the door switches were closed and door locks locked.

These changes, as well as others, will result from the association of the invention with elevators of different types and the invention is not to be understood as restricted or limited to the specific structure shown therein. It is to be construed as broadly novel as is commensurate with the appended claims.

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is:

1. In a system of the class described, an elevator car provided with a controller, a controller circuit, a switch in said controller circuit, mechanical means associated with the controller and with the switch and mechanically operated by the controller for automatically effecting a closing of the switch when the controller is in neutral and the car at rest, a lock associated with the shaft door of each floor, a switch associated with each lock and operated thereby, and electrical means associated with the door switches and controlled thereby for maintaining the controller circuit switch in closed condition when the car controller is moved from neutral to start the car provided that all the locks are in locked condition to close the door switches.

2. In a system of the class described, an elevator car provided with a controller, a controller circuit associated with the con troller, a switch in the controller circuit, mechanical means associated with the controller and with the switch and mechanically operated by the controller for effecting the closing of the switch when the controller is in neutral position and the car at rest, a lock associated with the shaft door of each floor of the building in which the elevator is installed, and electrical means controlled by all of said locks for maintaining the controller circuit switch in closed condition, when the controller is shifted from neutral position to start the car, provided that all of the locks are in locked condition.

In a system of the class described, an elevator car provided with a controller, a controller cirtaiit. associated with the controller, a stitch in the controller circuit, mechanical means associated with the controller and with the switch and mechanically operated by the controller for effecting the closing of the switch when the controller is in neutral position and the car at rest, a lock associated with the shaft door of each floor of the building in which the elevator is installed, and electrical means controlled by all of said locks for maintaining the controller circuit switch in closed condition,

when'the controller is shifted from neutral position to start the car, provided that all of the locks are in looked condition, in combination with manually operable mechanical emergency means for temporarily closing said switch to allow of movement of the car, even though the electrical switch maintaining means is ineffective.

4:. In a system of the class described, an elevator car provided with a controller, a circuit associated with the controller, a switch in said circuit, mechanical connections between the controller and the switch for positively and automatically eltecting a closing of the switch when the controller is in neutral position and the car at rest, locks associated with the floor doors ot' the shaft in which the elevator is installed, and electrical means controlled by said locks for maintaining the controller circuit switch in closed condition when the controller is moved out of neutral position. to start the car, provided that all of the door locks are in locked condition.

5. In a system of tie class described, an elevator car provided with a controller, a circuit associated with the controller, a switch in said circuit, mechanical connections between the controller and the switch for positively and automatically ellecting a closing of the switch when the controller is in neutral position and the car at rest, loclrs associated with the floor doors of the shaft in which the elevator is installed, and electrical means controlled by said locks for maintaining the controller circuit switch in closed condition when the controller is moved out of neutral position to start the car, provided that all of the door locks are in locked condition, in combination with manually operable mechanical emernemy means for temporarily closing said switch to allow or movement of the car, even tho h the electrical switch maintaining; means it ineffective.

6. In a system of the class described, an elevator car provided with a controller, a controller circuit associated therewith, a switch in the controller circuit, a gravity member cooperating with the switch and adapted to normally gravitate into a position to open the switch and render the controller ineffective to sart the car, mechani cal connections between the gravity member and the controller for automatically movi. the gravity member into position to close the switch when the car controller is in non"? position and the car at rest, a plurality o it switches corresponding to the respective floors of the building); in which the elevator is installed, and electrical means controlled by said switches and cooper ng with the gravity member to maintain the same position to hold the controller circuit sw closed, when the controller shi.

close the switch when the car controller in neutral position and the car at rest, a plurality of switches corresponding to the re spective floors of the building in which the elevator is installed, and electrical means controlled by said switches and cooperating with the gravity member to maintain the same in a position to hold the controller circuit switch closed, when the car controller is shifted from neutral to start the can-provided that the switches of all floors are closed, said electrical means being ineffective to move the gravity member in position to close the controller circut switch, but only to hold it closed after it has beenclosed by the connections between said switch and the controller.

8. In a system 01" the class described, an elevator car provided with a controller, a controller circuit associated therewith, a switch in the controller circuit, a gravity member cooperating with the switch and adapted to normally gravitate into a position to open the switch and render the controller ineffective to start the car, mechanical connections between the controller and the gravity member for lifting the gravity iii-ember into a position to close the switch when the car controller is in neutral position, switches on the floors of the building in which the elevator car is installed, and electrical means, operaole only when all of said switches are closed and the gravity member in a position to close the controller circuit switch, to hold said gravity member in such position when the car controller is moved "ti-om neutral position to start the car.

9. iii a system of the class described, an elevator car provided with a controller, a controller circuit associated with the controllcr, a switch in said circuit, mechanical con ections between the switch and the coir roller tor positively and automatically closing the m'mtroller circuit switch, a plurality o switches associated with the several floors of the buildi and a maintaining circuit OQlBlnlllQ to nunntain the controller circuit switch closed only after it l as been closed by the controller and when the switches of all tloors are closed.

it). system of the clais described, an

provided. who a controller, a

iii

controller circuit associated with the controller, a switch in said circuit, mechanical connections between the controller and switch to automatically close said switch when the controller is in neutral, a maintaining circuit for maintaining the switch closed after it has been closed by the controller, said maintaining circuit embodying a plurality of door switches associated with the shaft doors, and electromagnetic means, the maintaining circuit being fed electrically so that the positive current is required to pass through all of the door switches before passing to the electromagnetic means, whereby grounding of the circuit at the door switches or at any point on the positive side of the electromagnetic means will render said means ineffective to maintain the controller circuit switch closed and preclude the starting of the car.

11. In a system of the class described, an elevator car provided with a controller, a controller circuit associated with the controller, a switch in said circuit, mechanical connections between the controller and switch to automatically close said switch when the controller is in neutral, a maintaining circuit for maintaining the switch closed after it has been closed by the controller, said maintaining circuit embodying a plu rality of switches at the several floors of the building, and electromagnetic means, the maintaining circuit being fed electrically so that the positive current is required to pass through all of the door switches before passing to the electromagnetic means, whereby grounding of the circuit at the door switches or at any point on the positive side of. the electromagnetic means will render said means ineffective to maintain the controller circuit switch closed and preclude the starting of the car, in combination with manu ally operable mechanical emergency means adapted to be temporarily actuated by the car operator to effect the closing of the switch in the controller circuit even though the maintaining circuit is ineffective.

12. In a system of the class described, an elevator car provided with a controller, a controller circuit associated with the controller, a switch in said circuit, mechanical connections between the controller and switch for automatically closing said switch when the car controller is in neutral position and the car at rest, electrical means controlled by door switches for maintaining the controller circuit switch closed when the controller is moved from neutralposition to start the car, and mechanical emergency means adapted to be actuated by the car operator for temporarily maintaining the controller circuit switch closed in the event that the electrical maintaining means becomes inefl ective.

13. In a system of the class described, an

elevator car provided with a controller, an electric circuit associated with the car, a switch in said circuit, mechanical connections between the controller and the switch for automatically effecting a closing of the switch when the controller is in neutral and the car at rest, a plurality of switches positioned on the respective floors of the building in which the elevator is installed, a lock associated with the shaft door of each floor, each lock serving to'control the corresponding door switch, and electrical means associated with said door switches and controlled thereby for maintaining the car circuit switch in closed condition, when the car controller is moved from neutral to start the car provided that all the looks are in locked condition to close the door switches.

14. In a system of the class described, an elevator car provided with a controller, an electric circuit associated with the car, a switch in the car circuit, mechanical connections between the controller and the switch for automatically effecting the closing of the switch when the controller is in neutral position and the car at rest, a. lock associated with the shaft door of each fioor of the building in which the elevator is installed, and electrical means controlled by all of said locks for maintaining the car circuit switch in closed condition, when the controller is shifted from neutral position to start the car, provided that all of the locks are in locked condition.

15. In a system of the class described, an elevator car provided with a controller, an electric circuit associated with the car, a switch in the car circuit, mechanical connections between the controller and the switch for automatically effecting the closing of the switch when the controller is in neutral position and the car at rest, a lock associated with the shaft door of each floor of the building in which the elevator is installed, and electrical means controlled by all of said locks for maintaining the car circuit switch in closed condition, when the controller is shifted from neutral position to start the car, provided that all of the locks are in locked condition, in combination with manually operable mechanical emergency means for temporarily closing said sw tch to allow of movement of the car, even though the electrical switch maintaining means is ineffective.

16. In a system of the class described. an elevator car provided with a controller, an electric circuit associated with the car, a switch in said circuit, mechanical connections between the controller and the switch for positively effecting a closing of the switch when the controller is in neutral position and the car at rest, locks associated with the floor doors of the shaft in which the elevator is installed, and electrical means controlled by iso ill)

said locks for maintaining; the car circuit switch in closed condition when the controller is moved out of neutral position to start the car, provided that all of the door loclrs are in locked condition.

17. In a system of the class described, an elevator car provided with a. controller, an electrical circuit associated with the car, a switch in the car circuit, a gravity member cooperating with the switch and adapted to normally gravitate into aposition to open the switch and render the controller ineffective to start the car, mechanical connections between the gravity member and the controller for moving the gravity member into position to close the switch when the ear con troller is in neutral position and the car at rest, a plurality of door switches corresponding to the respective floors of the building in which the elevator is installed and electrical means controlled by said switches and cooperating; with the gravity member to maintain the same in a position to hold the car circuit switch closed, when the car con-- troller is shifted from neutral to start the car, provided that all of the door switches are closed.

.18. In a system of the class described, an elevator car provided with a controller, an electric circuit associated with the car, a switch in said circuit, mechanical connections between the switch and the controller for positively closing the car circuit switch, a plurality of door switches, and a maintaining circuit operable to maintain the car circuit switch closed only after it has been closed by the controller and when all of the door switches are closed.

19. In a system 01" the class described, an elevator car provided with a controller, an elec ic circuit associated with the car, a switch in said circuit, mechanical conuec tions between the controller and switch to close said switch when the controller is in neutral, a maintaining circuit for maintaining the switch closed after it has been closed by the controller, said maintaining circuit embodying a plurality of door switches, and electromagnetic means, the maintaining circuit being fed electrically so that the positive current is required to pass through all (it the door switches before passing to the electromagnetic means, whereby grounding oi the m cult at the door switches or at any point. on the positive side of the electromagne ic means will render said means incited tive to maintain the car circuit switch closed and preclude. the starting of the car.

20. in a system of the class described, an elevator car provided with a controller, an electric circuit associated with they car, a switch in sait circuit, mechanical connec tions between. the controller and switch to close said switch when the co troller is in neutral, a maintaining circuit 1 or maintaining the switch closed after it has been oleby the controller, said maintaining ciie embodying a plurality of door switches, and electromagnetic means, the maintaining circuit being fed electrically so that the posi- 'tive current is required to pass through all of the door switches before passing to the electromagnet means, whereby grounding of the circuit at the door switches or at any point on the positive side of the electromagnetic means will render said means ineffective to maintain the car circuit switch closed and preclude the starting of the car, in combinationwith manually operable mechanical emergency means adapted to be temporarily actuated by the car operator to effect the closing of the switch in the car circuit even though the maintaining circuit is ineffective.

21. In a system of the class described, an elevator car provided with a controller, an electric circuit associated with the car, a switch in said circuit, mechanical connections between the controller and switch to close said switch when the car controller is in neutral position and the car at rest, eleci'ical means controlled by door switches for maintaining the car circuit switch closed when the controller is moved "from neutral position to start the car, and mechanical emergency means adapted to be actuated by the car operator for temporarily maintaining; the car circuit switch closed in the event that the electrical maintaining means he comes ineffective.

22. In a system of the class described, an elevator car, a controller circuit associated therewith, a controller in the car forclosinp; this circuit at one point, controller circuit switch tor closing this circuit at another point, said switch being adapted to nor-- mally partake of open position, a plurality of door switches associated with the several floors of the building in which the elevator is installed, a door switch circuit including said door switches, means included in the door switch circuit for n'iaintaining the controller switch in closed position after it has been closed, said means being normally ineffective to close the controller circuit switch, and connections between the car controller and the controller circuit switch and adapted when the controller is in neutral to move the controller circuit switch into a position wherein it is responsive to the maintaining means of the door switch circuit.

23. In a system oi? the class described, an elevator car, a controller circuit associated therewith, a controller in the car for closing this circuit at one point, a controller circuit switch for closing this circuit at another point, said switch being adapted to normally partake of open position, a plurality door switches associated with the several iioorsot the" building in which the elevator is installed, a door switch circuit including said door switches, electro-magnetic means,

included in the door switch circuit for maintaining the controller switch in closed position after it has been closed, said means being normally ineffective to close the controller circuit switch, and connections between the car controller and the controller circuit. switch and adapted when the controller is in neutral to move the controller circuit switch into a position wherein it is responsive to the electro-magnetic maintaining means of the door switch circuit.

24. In a system of the class described, an elevator car, a controller circuit associated therewith, a controller in the car for closing this circuit at one point, a controller circuit switch for closing this circuit at another point, said switch being adapted to normally partake of open position, a plurality of door switches associated with the several floors of the building in which the elevator is installed, a door switch circuit including said door switches, means included in the door switch circuit for maintainin the controller switch in closed position a ter it has been closed, said means being normally ineflective to close the controller circuit switch and mechanical connections between the car controller and the controller circuit switch and adapted when the controller is in neutral to move the controller circuit switch into a position wherein it is responsive to the maintaining means of the door switch circuit.

25. In a system of the class described an elevator car, a controller circuit associated therewith, a controller in the car and adapted to close the controller circuit at one point, a controller circuit switch for closing the controller circuit at another point, said switch being normally maintained inopen position, a door switch circuit including an electromagnet normally ineffective to close the controller circuit switch until said switch has been moved into position to render it responsive to said electromagnet, and means controlled by the controller to move the controller circuit switch into a position wherein it will be responsive to the electromagnet of the door switch circuit when the car controller is moved into neutral position.

26. In a system of the class described an elevator car, a controller circuit associated therewith, a controller in the car and adapted to close the controller circuit at one point, a controller circuit switch for closing the controller circuit at another point, said switch being normally maintained in open position, a door switch circuit including an electromagnet normally ineffective to close the controller circuit switch until said switch has been moved into position to render it responsive to said electromagnet, and mechanical connections between the controller and the controller circuit switch to automatically move the controller circuit switch into a position wherein it will be responsive to the electromagnet of the door switch circuit when the car controller is moved into neutral position.

In testimony whereof, I have signed my name to this specification.

FRANZ A. BOEDTCHER. 

